Going after the cartel kingpins made the problem worse, say aides to Mexico's new president. But killing it would jeopardize significant U.S. funding.

MEXICO CITY — You find the capos of the drug trade, and you arrest them or kill them.

That, in its simplest form, was the idea behind the so-called kingpin strategy that former Mexican President Felipe Calderon pursued with zeal for most of his six-year term. As his administration drew to an end this year, he would often mention, as a point of pride, that his government had taken out two-thirds of Mexico's 37 most wanted criminals.

But as new President Enrique Peña Nieto rolled out his crime-fighting strategy this week, his team was explicit about the trouble that "kingpin" had wrought:

On Monday, Interior Minister Miguel Angel Osorio Chong said the strategy caused a fragmentation of criminal groups that had made them "more violent and much more dangerous," as they branched out into homicide, extortion, robbery and kidnapping.

The next day, Jesus Murillo Karam, the new attorney general, said in a radio interview that the strategy was responsible for spawning 60 to 80 small and medium-sized organized crime groups.

But just because the strategy has taken some hits doesn't mean it's dead. And Peña Nieto, who took office Dec. 1, is unlikely to kill it.

His Institutional Revolutionary Party, or PRI, which ruled Mexico as a quasi-dictatorship for 70 years, was notorious for looking the other way when it came to organized crime, and Peña Nieto, 46, has promised that the party will not return to its old habits.

Peña Nieto is also unlikely to jeopardize the generous security assistance provided by the United States, which helped design the kingpin strategy. The U.S. is intimately involved in carrying it out, providing intelligence on drug leaders' whereabouts and spending millions to strengthen the Mexican security forces who act on that intelligence.

All of which probably explains why, shortly after the ministers' criticism of kingpin, a top presidential advisor told The Times that the new government had no plans to abandon it.

"That will not stop at all," said the advisor, who declined to be identified because he was not authorized to speak on the record.

But there will be changes. The pursuit of capos, the Peña Nieto advisor said, will be a quieter affair than during the Calderon administration, their neutralization presented with less fanfare. Calderon's aggressive crackdown on cartels has been criticized as having done little to stop the flow of drugs while exacerbating violence, resulting in tens of thousands of deaths.

Peña Nieto, in a speech Monday before Mexico's National Public Security Council, said that "evaluation and feedback" would be a pillar of his crime-fighting strategy, though he was vague on the details. He emphasized, as he has many times, that his government would make it a top priority to focus on solutions that reduce the number of homicides, kidnappings and extortions.

Osorio Chong said that between 2006, when Calderon's term started, and 2011, kidnappings increased 83%; violent robberies, 65%; and highway robberies, 100%.

The kingpin strategy was based on a similar plan in Colombia in the 1990s, said Shannon O'Neil, the senior fellow for Latin American studies at the U.S.-based Council on Foreign Relations. Colombian cartel leaders at the time were directing their violence against the state, targeting high-profile federal officials for assassination. When the capos were taken out, the threats to the federal government were reduced.

Peña Nieto's full security plan is still coming into focus, with some elements more specific than others: He has promised to create a gendarmerie to patrol the most violent areas, and 15 federal police units that will focus only on extortion and kidnapping. He has also called for a revision of arraigo, the practice of detaining suspects for up to 80 days for serious crimes that was commonly used under Calderon but which rarely resulted in the suspect being prosecuted.

In his speech Monday, Peña Nieto also vowed to launch a national human rights program, more robust crime prevention programs, better planning and coordination, plus a system, as yet undefined, to evaluate it all.

Jorge Chabat, a professor at Mexico City's Center for Economic Research and Teaching, said Peña Nieto was in a difficult position because he wants to show that he'll fight the drug war in a way that distinguishes him from Calderon, but at the same time, "there's little room to maneuver in terms of changing the security strategy. In reality, there aren't many options."

Columnist Carlos Puig, writing in the newspaper Milenio, criticized the speech for lacking substance and detail. But he was pleased that Peña Nieto was striking a different tone than Calderon, a tone decidedly more wonkish and not "the speech of a valiant warrior."